<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <!-- 准备好一个“容器” -->
  <div id="test"></div>

  <!-- 引入react核心库 -->
  <script type="text/javascript" src="../js/react.development.js"></script>
  <!-- 引入react-dom，用于支持react操作DOM -->
  <script type="text/javascript" src="../js/react-dom.development.js"></script>
  <!-- 引入babel，用于将jsx转为js -->
  <script type="text/javascript" src="../js/babel.min.js"></script>

  <script type="text/babel">
    class Demo extends React.Component {
      /*
        React.createRef调用后可以返回一个容器，该容器可以存储被ref所标识的节点,该容器是“专人专用”的
      */
      myRef = React.createRef()

      showData = () => {
        alert(this.myRef.current.value)
      }

      saveInput = (c) => {
        this.inp1 = c
      }

      render() {
        return (
          <div>
            <input ref={this.myRef} type="text" placeholder="点击按钮提示数据" />
            <button onClick={this.showData}>点我提示左侧的数据</button>&nbsp;
          </div>
        )
      }
    }
    ReactDOM.render(<Demo />, document.getElementById('test'))
  </script>
</body>

</html>